Articular cartilage is a smooth, resilient tissue which covers the opposing ends of bones and facilitates the smooth movement of the bones relative to one another. However, when articular cartilage is damaged (e.g., through injury or prolonged wear), subsequent motion of the bones tends to increase that damage, ultimately causing the cartilage to wear away completely. When this occurs, the bones rub directly against one another, typically resulting in substantial pain for the patient and reduced mobility of the joint. In many cases, such damage to articular cartilage can lead to osteoarthritis.
Microfracture surgery is an orthopedic procedure which can help to restore articular cartilage. More particularly, microfracture surgery creates tiny fractures in the cortical bone bed disposed immediately below the damaged articular cartilage. These fractures permit blood and bone marrow to seep out of the underlying cancellous bone and essentially create blood clots which release cartilage-building cells. These cartilage-building cells then result in the formation of replacement cartilage.
To date, microfracture surgery is typically performed using a small, sharp pick or awl to create the small microfracture holes in the cortical bone. However, such picks or awls are generally used by driving them longitudinally, e.g., with a hammer or mallet, thereby requiring substantially direct linear access to the bone surface which is to receive the microfracture therapy. Furthermore, where the microfracture must be created in a bone surface which is not substantially aligned with the angle of access, it can be difficult to generate the forces required for the pick or awl to penetrate the hard cortical bone and release blood and bone marrow from the underlying cancellous bone.
In many cases, e.g., certain sites on the lower femur, such direct linear access to the microfracture site may be readily available. However, in other cases, intervening anatomical structures may make it difficult or impossible to use a conventional pick or awl to perform the microfracture surgery on the bone. This is particularly true where the microfracture surgery is to be performed arthroscopically. By way of example but not limitation, it can be difficult or even impossible to arthroscopically perform microfracture therapy on the acetabular cup of the hip using a conventional pick or awl, given the anatomical constraints typically imposed in arthroscopic hip surgery.
The present invention is intended to provide a novel method and apparatus for performing arthroscopic microfracture surgery, particularly in locations where it is difficult to utilize a conventional pick or awl in the microfracture surgery.